ASP solvers address several reasoning tasks that go beyond the mere computation of answer sets. Among them are cautious reasoning, for modeling query entailment, and optimum answer set computation, for supporting numerical optimization. This paper reports on the recent improvements of the solver wasp, and details the algorithms and the design choices for addressing several reasoning tasks in ASP. An experimental analysis on publicly available benchmarks shows that the new version of wasp outperforms the previous one. Comparing with the state-of-the-art solver clasp, the performance of wasp is competitive in the overall for number of solved instances and average execution time.